In this study, we investigated mechanisms by which regulatory B cells (Bregs) suppress CNS autoimmune diseases such as Uveitis or Multiple Sclerosis. These studies focused on Bregs that secrete IL-10, IL-27 or IL-35. We have isolated these Breg cells from human blood or bone marrow and in mice they were isolated from the spleen or peritoneal cavity. We are now characterizing the Breg cells transcriptomes by single-cell RNA-Seq (scRNA-Seq), Chip-Seq, ATAC-Seq. We have also isolated IL-35 containing exosomes from IL-35-producing Bregs (i35-Bregs), demonstrated that they suppress experimental autoimmune uveitis (EAU), suggesting that exosomes derived from Bregs can be exploited for adoptive immunotherapy in CNS autoimmune and neurodegenerative diseases.